CODEWITHSUNDEEP
javaspringspring-mvc
Soumya Tripathy
Soumya Tripathy

Reputation: 31

Spring WebApplicationInitializer

Recently I've been learning spring java based configuration. I tried to replace the web.xml with WebConfig and WebApplicationInitializer.

Whenever I'm requesting the url: http://localhost:8080/spring-demo/greeting.html I'm getting 404 description The requested resource is not available. Below are my project details.

WebConfig.java

package com.soumya.spring;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;

@Configuration
@EnableWebMvc
@ComponentScan(basePackages = "com.soumya.spring")
public class WebConfig {

}

WebAppInitializer.java

package com.soumya.spring;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRegistration;

import org.springframework.web.WebApplicationInitializer;
import org.springframework.web.context.ContextLoaderListener;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
import org.springframework.web.servlet.DispatcherServlet;

public class WebAppInitializer implements WebApplicationInitializer {

    @Override
    public void onStartup(ServletContext servletContext) throws ServletException {      
        WebApplicationContext context = getContext();
        servletContext.addListener(new ContextLoaderListener(context));
        ServletRegistration.Dynamic dispatcher = servletContext.addServlet("DispatcherServlet", new DispatcherServlet(context));
        dispatcher.setLoadOnStartup(1);
        dispatcher.addMapping("*.html");
    }

    private AnnotationConfigWebApplicationContext getContext() {
        AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext();
        context.setConfigLocation("com.soumya.spring.WebConfig");
        return context;
    }

}

Controller

package com.soumya.spring.controller;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
public class HelloController {

    @RequestMapping(value = "/greeting")
    public String greeting(Model model) {
        model.addAttribute("greeting", "Hello World!");
        return "greeting.jsp";
    }

}

Project Structure Image

Project Structure

Upvotes: 1

Views: 16482

Answers (3)

Prathamesh Beri
Prathamesh Beri

Reputation: 141

First of, your url should not have .html or .jsp at the end. The url will be http://localhost:8080/spring-demo/greeting

In your specific WebApplicationInitalizer, your DispatcherServlet should be mapped to /greeting controller instead of " *.html ".

dispatcher.addMapping("/greeting");

Also, Your DispatcherServlet (WebConfig.class in your code) does not have a ViewResolver Bean defined. The ViewResolver is in charge of mapping a view name( like 'greeting.jsp' which is returned by your HelloController) to the view implementation( the actual 'greeting.jsp' file which could be present in the /WEB-INF/ folder.

I have changed your WebConfig class to include a ViewResolver bean-

package com.soumya.spring;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import org.springframework.web.servlet.view.InternalResourceViewResolver;


@Configuration
@EnableWebMvc
@ComponentScan(basePackages = "com.soumya.spring")
public class WebConfig extends WebMvcConfigurerAdapter {

@Bean
public ViewResolver viewResolver() {

        InternalResourceViewResolver irvr = new InternalResourceViewResolver();

        irvr.setPrefix("/WEB-INF/views/"); //your "greeting.jsp" file should be here
        irvr.setSuffix(".jsp");
        irvr.setExposeContextBeansAsAttributes(true);
        return irvr;

    }
}

Upvotes: 1

nani
nani

Reputation: 1

If you are using spring MVC recent version , please replace configlocation with below

   from context.setConfigLocation("com.soumya.spring.WebConfig");

to context.register(WebConfig.class). It should work.

Upvotes: 0

Marta Ginosian
Marta Ginosian

Reputation: 117

An example of initialization with comments.

    public class Initializer implements WebApplicationInitializer {
    @Override
    public void onStartup(ServletContext servletContext) throws ServletException {
        // Creates context object
        AnnotationConfigWebApplicationContext ctx = new AnnotationConfigWebApplicationContext();

        // Registers annotated configurations class
        ctx.register(Configurations.class);

        // Sets ContextLoaderListener to servletContext
        servletContext.addListener(new ContextLoaderListener(ctx));

        // Passes servlet context to context instance
        ctx.setServletContext(servletContext);

        //Registers dispatch servlet and passes context instance
        ServletRegistration.Dynamic servlet = servletContext.addServlet("dispatcher", new DispatcherServlet(ctx));

        //Maps URL pattern
        servlet.addMapping("/");

        //Sets creation priority
        servlet.setLoadOnStartup(1);

        //Registers security filters
        FilterRegistration.Dynamic security = servletContext.addFilter("springSecurityFilterChain", new DelegatingFilterProxy());

        // Sets dispatcher types a security filters to be applied
        EnumSet<DispatcherType> dispatcherTypes = EnumSet.of(DispatcherType.REQUEST, DispatcherType.FORWARD);
        security.addMappingForUrlPatterns(dispatcherTypes, true, "/*");
    }
}

Upvotes: 0

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